This tutorial covers how to do solid increases and decreases while making a foundation row. ("Solid" meaning it won't leave a large hole).

You should get familiar with how to do solid increases and decreases in general before attempting them in a chainless foundation.

Let's start by making a solid decrease first. Outside of the chainless foundation technique, these stitches are normally written as dc3tog or sc2tog or some such. The basic description of this instruction is to work the number of stitches indicated, but only up to the last "yo, pull through", leaving an extra loop on your hook. Once you have the required number of stitches, you yarn over and pull through all loops on your hook.

What this does, is to join the tops of the stitches into one stitch.

In chainless foundation, you start by making your first stitch, all the way up until just before the last "yo, pull through". I'm doing double crochet, so this is what my first stitch looks like:

Get all of the loops on:

ch1:

Finish the stitch, stopping short of the last "yo, pull through":

Repeat that for as many stitches as you need, then do a final, "yo, pull through all loops"(This is dc2tog)

When making a solid increase in crochet, you work multiple stitches into one spot. This is usually written as "3dc in next st" or "3dc inc" or some such.

To do this in chainless foundations, you work the first stitch of the group as a foundation stitch, and then work the rest of the stitches in the group into the base of that first stitch (as regular stitches, not foundation stitches). Once your increase is done and you're ready to work in a straight line again, you insert your hook in that same spot yet again, but start making foundation stitches again.

Here is is in dc stitches:

Start with a foundation stitch:

Make a dc stitch (NOT a foundation dc) into the ch1 at the bottom of the previous stitch:

Do that as many times as you need to, always inserting your hook into that same spot. Then, work a foundation double crochet to continue on in a straight line: